Name two incidents that have created a great deal of interest in the planets Mars and Jupiter, respectively.

Mars

After Venus, Mars is our closest neighbour. It seems very earth-like. There are ice-caps on its poles, drifting white clouds and raging dust storms in its atmosphere. Seasonally changing patterns occur on its red surface. There are large dark areas on its surface called maria (meaning 'seas'). It even has a twenty-four-hour day. Mars experiences summer and winter seasons, each of which lasts for almost six earth mkths. However, the planet's distance from the Sun causes these seasonal changes to be more extreme. It is tempting to think of Mars as an inhabited world. In 1877, the Italian astronomer, Schiaparelli, observed an intricate network of single and double lines crisis-crossing the bright arps of the planet Mars. He gave them the name of canali. Canali in Italian means channels or erooves. But it was promptly translated into English as 'canals'.

Jupiter

The most outstanding feature on t h s~ur face of Jupiter is the Great Ked Spot . It is a long oval area which is so huge that two earths. side by side, could be dropped through it. Sometimes it becomes pale plnk in colour and at other times a fiery orange red. For long, the Great Red Spot puzzled the astronomers. Th e Pioneer and Voyager missions to Jupiter revealed that the Red Spot is a huge cyclonic disturbance in the atmosphere. Jupiter is mainly a quick-spinning ball of gas and liquid with no solid surface. It also emits radio waves. Its composition, size and the number of moons gave rise to the idea that Jupiter is not a planet but rather a star with a "sdar system" of its own, that did not start 'burning'. It is estimated that if Jupiter,were just ten times heavier, it could have started to produce its own energy like the Sun

Describe two major ways of exploring the universe. Discuss two kinds of information that each of them has provided about the universe.

Observatories in Space-

With the coming of the Space Age, observation&equipped with telescopes and cameras could be placed right in space, beyond the Earth's atmosphere. An observatory in space may be in the form of an orbiting satellite like the Unmanned Orbiting Solar Observatories, Orbiting Astronomical Observatory, Skylab, Einstein Observatory, IRAS (Infra Red-Astronomy Satellite) and many others. An observatory may also be stationed on the Moon or any other planet having suitable temperature and other conditions. Instruments are also put aboard high flying balloons, rockets and aircraft to record observations. These observatories can record radiation from a cosmic object in the regions of the spectrum such as the IR, UV, gamma rays and X-rays that do not penetrate the Earth's atmosphere.

Visiting the Neighboring Worlds-

As space research came of age, it became possible for us to send spacecraft to other planets and even land men and instruments on the Moon. These ventures also provided a rich stock of information about the Solar System. For instance, astronauts of the Apollo mission to the Moon in the nineteen seventies brought back lllnar rocks and soil samples, photographic of the lunar surface' and Left several instruments there for further study. We have been able to send spacecraft, also called probes, across the Solar System to know more about our planetary neighbors. Space probes have visited a number of planets and a host of their moons, and successfully landed and operated on the surfaces of Mars and Venus.

Describe the features of the Indian state and the social organization that helped the growth of science and technology in the Maurya and Gilpta period.

Indian state and ;ts policy is described in detail in Arthasastra. written by Kautilya, the great minister of Chadragupta. According to him, it was a highly centralised state which was the principal owner of industry as well as the greatest producer of commodities. The commodities produced by the state were bought and sold by traders. This large revenue was used to maintain a massive army, of half a million men, which was used to acquire land, protect the land and the frontiers, and maintain law and order in the vast empire. Brahmins, as agents of the crown, spearheaded the move into the new territories. A process was initiated whereby tribal deities were equated with standard Aryan gods. Totemic deities such as primaeval fish,
tortoise, monkey, bull etc. were intraduced into the traditional Hindu scriptures as companions of major gods like Vishnu, or their reincarnations. The Brahmins could impose the caste structure quite easily, as they played an important part in introducing a new mode of agriculture and of commodity production to the tribal people.The superstitions, which provided the ideology of the lower castes, in effect, kept them in subjugation. Finally, these superstitions came to have an adverse effect on the growth of scientific ideas. It is not surprising that Asoka reacted to the development of this superstitious and ritualistic culture by adopting the teachings of Buddha. Buddhism, in its early form, devoid of rituals C and superstitions, stood against oppression and advocated a simple and meaningful life based on reason and compassion.

Compare the life styles and the level of scientific and technical know how of sixteenth century Europe and sixteenth century India. What are the reasons that keep India lagging behind the western countries in almost all areas related to development?

In science, this period from the mid-sixteenth century to the mid-eighteenth century includes ;he first great triumphs of the new observational, experimental approach. This new approa n together with'the development in science and technology during tne Renaissance, amounted to a "Scientific Revolution". Technically, this period was of steady advance without any revolutionary inventions. The increasing demand for iron led to development of new blast furnaces. The shortage of wood for iron-smelting led to widespread use of coal. From then on. the centre of industry was to move towards the coal fields. With time, the demand for limited resources increased, forcing the search for new resources and techniques. Thisalso altered the attitudes towards change and novelty, which could not be shunned anymore. You may recall that in the regimented feudal society, new ideas and change were resisted It was in this atmosphere that European science grew to maturity, The first institute for teaching science, the Gresham College, was opened in England in 1579. As we have already seen, the revolQionary Copernican model of the solar system helped in improving astronomical tables, What the theory lacked was an accurate description of the orbits of the planets. Let us now see what the few scientific developments An interesting feature in the early phase of this period was that colonial scientists would try their hand at several fields simultaneously and each scientist was, in fact, a botanist, geologist, geographer and educator-all rolled into one. As data-gatherers, the individual scientists were efficient. However, for analysis and drawing conclusions, they had to depend upon the scientific institutions in Britain, which received such data from many colonies. It was followed by Agricultural-Horticultural Society of India (1817), Calcutta Medical & Physical Society (1 823), Madras Literary and Scientific Society (1818), and the Bombay Branch of the Asiatic Society (1829). These societies rendered invaluable service, particularly through their journals which compared very favourably with the European ones.